Device for preventing friction between the leaves of leaf-springs



T. s. HAMILTON. DEVICE FOR PREVENTING FRICTION BETWEEN THE LEAVES OF LEAF SPRINGS.

APPLICATION FILED DEC- I8, I9I9. I I,371,166. Patented Mar. 8,1921.

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'rnomas s. HAMILTON, or

,DEVICE FOR PREVENTING FRICTION BE KANSAS CITY, MISSOURI.

TWEEN THE LEAVES OF LEAF-SPRINGS.

Specification of Application filed December 1 T 0 all whom it may concern:

Be it known that I, THOMAS S. HAMILTON, a citizen of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Devices for Preventing Friction Between the Leaves of Leaf-Springs, of which the following is a specification.

This invention relates to new and useful improvements in a device for preventing friction between the leaves .of leaf springs.

Heretofore lubrication of leaf springs has generally been accomplished by separating the leaves of the spring and placing oil between the same with an oil can or the like. An effort has been made to produce a lubri eating strip which may be placed between the leaves of the spring affording a continuous oil supply therefor, but all of these strips with which I am familiar have been terme diate the formed of compressible material soaked with a lubricating agent. The feature of com-' pressibility is an undesirable one in that the compressibility of the strip allows play in the spring and causes them to become loose and break. Also when this carrier strip has been subjected to continuous action for some time, it becomes so compressed that it slips out between the leaves of the spring.

The use of a read flowing lubricant in such a carrier is highly undesirable in that the action of the spring squeezes oil from the carrier and it collects upon the edges of the spring and dirt and dust from the road adheres thereto. Then in cleaning the spring to remove the grease, it isnecessary to use gasolene and this use of gasolenehas a tendency to destroy the lubricating properties of the lubricant in the strip.

I have found that by placing a strip of hard material having a smooth surface inleaves of the spring, the necessity of a further lubricant for the spring becomes unnecessary. This strip may be either a fiber or of cast iron or the like, smoothly finished to eliminate all unnecessary frictional surface. If desired, this hard material strip may be placed in position without the use of any additional lubricant or the strip may be advantageously used in connection with a hard lubricant of the type described in my application, Serial No. 320,683, filed August 29, 1919.

Other objedts and advantages of the in- Patented Mar. 8, 1921.

s, 1919. Serial No. 345,813.

Letters Patent.

vention will be obvious throughout the course of the following description.

In the accompanying drawings wherein is illustrated the use of a lubricating strip of the type described in a spring,

Figure 1 is 'a side elevation of a leaf spring having interposed between the ends of the leaves my antifriction strip.

Fig. 2 is a similar view showing the strips extending entirly'through the length of the leaves of the spring. a

Fig. 3 is a section taken on the line 3-3 of Fig. 1.

Fig. 4 is a side'elevation partly in section of a fiber strip having applied thereto a dry lubricant, and

Fig. 5 is a similar view showing the use of double strips.

Referring now more particularly to the drawings, the numeral 10 indicates the leaves of the spring having disposed therebetween an antifriction strip 11. This strip consists in the present instance of a sheet of fiber of approximately two hundredths (.02) of an inch in thickness, having at least one side treated to form an antifriction surface. This antifriction surface may be formed either by polishing or by applying toone side thereof hard lubricant. course limit myself to the use of fiber but may use any similar antifriction substance, as for example cast iron smoothly finished and polished or any other material having theproperties of high compressibility and of taking on a high polish.

In some cases it is desirable to apply to the strip, upon one side thereof, an adhesive 12- and upon the other side a composition similar to that described in the above mentioned application. This composition consists of the following ingredients:

A binder, viz: shellac, silicate of soda, varnish or the like, 1 qt.

A dry lubricant, viz: fine powdered graphite, mica or soapstone, 1 lb.

Powdered alum, 1 oz.

These ingredients are mixed to form a paste or paint which is spread upon the strip as at 13 and sprinkled with heavy flaked graphite l t. The strip is then placed under pressure in a warm press for approximately twenty minutes and subsequently baked in an oyen. is placed intermediate the springs, the side to which the adhesive has been applied will I do not of When a strip of this type comprising a strip of adhere to the leaves of the spring against which it contacts and the opposite side of the strip affords a bearing surface for the leaf which it contacts.

It will sometimes be found convenient to place two of the strips bearing adhesive upon one side and the coating of dry lubricant upon the other face to face between the spring, in which case the adhesive sides are placed outwardly to adhere to the adjacent face of the spring and the surfaces of the strips bearing the lubricant act uponone another to form a bearing surface.

I have also found that the above named composition is extremely efficient in painting abutting moving faces, as for example the parts of a hinge or any parts which may rub together and cause friction and noise. The paint when applied to the parts hardens thereon and forms a noiseless bearing surface thus eliminating various creaks and other noises arising in automobiles due to shifting parts. The leaves of the springs themselves may be treated in this manner.

lVhile I have statedthat the strips may be used with the compound above described, it is to be understood that the strips may be used without any such application of dry lubricant and may be simply placed between the leaves of the spring.

What I claim is: I 1. A lubricating strip for comprising a strip of fiber provided on one side with a layer of lubricant and means on the other side for securing it to one of the leaves of the spring.

2. A lubricating strip for leaf springs comprising a strip of fiber provided on one side with an antifriction surface and means on the opposite side for securing it to one of the leaves of the spring.

3. A lubricating strip for leaf springs fiberprovided upon leaf springs comprising a 'strip of fiber provided upon one side thereof with an adhesive and upon the other side with a layer of dry lubricant. 5. A lubricating strip for leaf springs comprising a strip of fiber provided upon one side; thereof with an adhesive and upon the other side with a layer of hard lubricant. 6. A lubricating strip for leaf springs comprising astrip of fiber provided upon one'sidethereof with an adhesive and upon the other side with a layer of lubricant comprising shellac, graphite and alum.

1. A lubricating strip for leaf springs fiber provided upon comprising a strip of one side thereof with an adhesive and upon the other side with a layer of hard lubricant comprising shellac, a dry lubricant and alum and a filler applied to the outer face of said layer of lubricant.

8. A lubricating strip for leaf springs comprising a strip of fiber provided upon .one side thereof with an adhesive and upon the other side with a layer of hard lubricant comprising a dry lubricant and a watery binder adapted to harden under the action of heat and pressure.

9. A lubricating strip for leaf sprlngs comprising a strip of fiber provided upon one side thereof with an adhesive and upon the other side with a layer of hard lubricant comprising graphite and a watery binder adapted to harden under the action of heat and pressure and a filler applied to the outer' face of said layer of lubricant.

In testimony whereof I affix my signature in presence of two witnesses. v

THOMAS S. HAMILTON. lVitnesses:

I. G. SAMPLE, GARLAND B. WHrrsIrT 

